


Bonding

by ApatheticSquirrel



Category: Fate/Grand Order
Genre: Angst, Blood and Violence, Enemies to Friends to Lovers, F/M, Fluff, Focus is Cú Alter but the other Cús love you already, Hurt/Comfort, Mild Language, No Solomon Spoilers, Pre-Solomon, Protectiveness, Romance
Language: English
Status: In-Progress
Published: 2019-05-01
Updated: 2019-05-03
Packaged: 2020-02-10 17:57:10
Rating: General Audiences
Warnings: No Archive Warnings Apply
Chapters: 2
Words: 2,793
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/18665467
Author URL: https://archiveofourown.org/users/ApatheticSquirrel/pseuds/ApatheticSquirrel
Summary: You've summoned a new and powerful berserker to your Chaldea. You seem to be the only one delighted by his arrival.





	1. Summoned

**Author's Note:**

> This is dedicated to my precious BerserCú who I have invested a stupid amount of love and time (and money) into. Its a sin I haven't written for him, but I love FGO and my Chaldea so this will be a lot of fun to do. Having recently got him to bond level 10, I was inspired to write for him based on my Chaldea. To all the Cú lovers out there, this ones on me :3

  Your eyes stung from the bright rainbow of magical light. You took a step back from the summoning circle as you felt the immense magical pressure of whoever you had called. Da Vinci placed a supportive hand on your shoulder as she smiled knowingly at the great plume of magic before you both. The command seals on your hand burned as your newest contract was forged. Holding your aching hand to your chest, you watched with wide eyes as the light dissipated to reveal a painfully familiar face.

 

  “I am Cú Chulainn, summoned at your request!” His red eyes looked down at you with mild irritation as he noticed your owlish expression at having summoned someone like him.

 

  “… My color has nothing to do with you.” The Alter muttered as he stepped forward and regarded you fully, glancing from Da Vinci’s inquisitive stare to your excited eyes. He frowned.

 

  “W-Wow! I can’t believe I was able to summon you! Welcome to Chaldea, I’m glad to have your help here.” You mused, introducing yourself to him. Cú’s red eyes narrowed at your friendly words before looking past you and walking towards the exit of the summoning chamber. You took his cold demeanor in stride, recalling his unfortunate existence from the Fifth Singularity. _Perhaps this could be a second chance for the man._   

 

  The hand on your shoulder gave you a light squeeze as Da Vinci cleared her throat to get your attention. Though wearing her typical, care-free smile, her bright eyes held concern as she spoke.

 

  “I know what you’re thinking, but this is a servant you may need to tread carefully when dealing with.”  Her soft voice held the wisdom and heart you appreciated from her as you brought your hand over hers. A determined expression she knew all too well came to your face as she sighed in exasperation at you.

 

  “Mash isn’t going to like this, y’know?” Da Vinci teased as she let go of you and went to report the arrival of the Alter to Romani. You chuckled but hurried past her towards the exit where Cú Alter had gone. You loved getting to know servants and helping them find comfort at Chaldea, but Cú Chulainn Alter was something else entirely. You had already summoned Caster, Lancer, and Proto from your early days at Chaldea so you already had personal interest in the Berserker.

 

  A small frown fell to your lips as you thought of the heartbreak you felt in America when you learned of the man’s fate. Cú Chulainn, in all his other forms, was a servant you loved dearly. He was loyal, a delight to be around, and someone you could always rely on. To have then come upon Alter, who looked at you with only bloodlust back then, was painful to say the least. No matter how much the other Cú Chulainns comforted you and swore themselves to you during the Fifth Singularity, your heart bled for the Alter. Even as the Mad King sneered at you back then and attempted to murder you every chance he could, you never held it against him. You felt sorry for him. After all, you knew the real Cú Chulainn. It wasn’t Alter’s fault for what Medb had forced him to become.

 

  Clenching your fists at your side, you quickened your pace and followed the clean hallway to find your new Berserker. He may be an Alter, but he was still Cú Chulainn. You were going to do everything in your power to understand him and hope he’d one day understand you.


	2. Bond 1

**Summary for the Chapter:**

> THIS WAS SUPPOSED TO BE SHORT BUT SHIT I DON'T KNOW WHAT HAPPEN. All the chapters after this will be solely focused on Alter I promise.

  It had been a rocky time trying to get along with Cú Chulainn Alter. After catching up to him that first day, you were able to give a brief tour of Chaldea to which he silently followed. Any servants who had the misfortune to run into you both were met with a harsh glare and cold shoulder from him while you tried to apologize, promising to speak with them later. Cú Alter seemed unbothered by the discomfort or offense he caused to his now allies, but thankfully the servants you encountered were the more docile ones of your roster.

 

  An awkwardly brief encounter was when you showed the berserker to one of the common rooms. As luck would have it, the other Cú Chulainns were lounging on the sofa chatting at their leisure while a movie played on the television. As you entered the room the men were quick to turn their attention to you and your companion.

 

  “Yo, Master.” Lancer Cú was first to greet you, his crimson gaze directed to his Alter with an unreadable cool. Though his words were delivered in a carefree manner, his chilling composure and neutral expression made you tense as Caster and the youthful Proto held similar expressions. You smiled regardless of your nerves as you gestured to Cú Alter, feeling your anxiety go up at the way his eyes narrowed at them.

 

  “This is Chaldea’s newest Berserker. I hope you all get along!” You applauded yourself internally for not stuttering as you spoke. Proto Cú gave small nod in greeting before returning his attention to T.V; Caster raised an eyebrow at you and shrugged in a non-committal sort of way, turning back around like Proto. Cú Lancer kept his gaze squarely on Alter, the tension between them making you tense as you worried there may be conflict.  Lancer’s easygoing voice snapped you from your thoughts though.

 

  “Of course, Master, but you sure know how to pick em. Let me know if you need me.” His casual tone helped you relax some, but not much as he tossed a toothy smirk at the two of you that resembled more a snarl before he turned back to the television. The reply to his words died on your lips as the tall figure beside you growled lowly, so low you hardly noticed it.

 

  “Tch, take me to my room.” Was all he muttered as he left the room; you went after him and escorted him to his quarters. In hindsight, the first day could have gone significantly worse. There were no fights, just rude manners coming from him. Although the reactions of your other Cú Chulainns were not something to brush aside. You could tell they had less than favorable opinions on the matter, though only Lancer really expressed his willingness to challenge Alter. You made a mental note to speak with them as soon as you could to really hear them out as you went towards your room.

 

  As you approached the familiar door, Mash was leaning against the doorframe and perked up at seeing you.

 

  “Senpai! I heard who you summoned…um… are you alright?” Worry was all over her face as Fou was tucked in her arms as she held the poor animal for comfort. You smiled warmly at the blushing girl as you nodded and went to open your door.

 

  “I’m fine, why wouldn’t I be? Alter is just another servant that needs patience and understanding.” You answered as you opened the door and gestured for her to go inside, knowing you’d have to let her get her feelings out before she’d come around to the situation. Mash thanked you and entered your room, taking a seat on the chair near your bed as you sat on the mattress facing her.

 

  “I know you’re really good at making contracts with all kinds of servants, its admirable really… I just can’t forget what he _did_ back in the Fifth Singularity. Senpai, I just can’t believe you summoned someone like _him_.” Mash sighed her long bangs covering her face though her lips fell into a small frown. You hummed in thought as her words were carried through your mind. Crossing your legs, you leaned back on the bed before sitting up as you found your voice.

 

  “Mash, you really ought to leave the worrying to me. Remember how anxious you were when I summoned Shuten- Douji and Ibaraki- Douji? You were glued to my hip and had your shield ready if Shuten even smirked in my direction.” The pink haired girl blushed fiercely as she slid some of her hair from her eyes, nodding at your words. You continued.

 

  “Though it took time, you came around to seeing that there was more to them then how they carried themselves. I even see you laugh and joke with Shuten sometimes. I know it might seem crazy, but just trust me okay?” You stood from your bed and extended a hand towards your Demi-Servant. Looking up and meeting your resolute gaze, Mash felt her heart pound in her chest as she smiled at you with admiration. Taking your hand, she stood as well and you hugged her.

 

  “Thank you, Senpai. I always believe in you.”

 

After your talk with Mash, the girl left your room, wishing you goodnight as it had gotten late. As you finished changing into your PJs, there was a knock at your door. Yawning, you went to open the door expecting it to be Lancer Cú Chulainn as he typically enjoyed hanging out in your room with you. (And with his reaction to seeing Alter, you wouldn’t be surprised if Lancer came by about that too.) To your surprise, your angel of the battlefield stood in your doorway instead.

 

  “Florence? What’s up?” You asked, noticing her rather serious expression. Her appearance was as immaculate as always, her posture straight as her eyes gave you a quick look over.

 

  “Master, may I join you tonight?” Though phrased as a question, the Berserker was already entering your room before you agreed. Not that you minded really, besides you knew the stubborn nature of the nurse.

 

  “I was just about to go to bed, is that okay?” You asked her as you shut the door and headed towards your bed. She gave a curt nod and watched as you went and got under the covers. Nightingale clicked off the lights of your room before moving to sit in the chair at your bedside. If you hadn’t spent so much time with the Berserker on and off the battlefield, you’d have been nervous about her behavior. Her eyes betrayed her intentions though as she glanced from the locked door to you, her small frown giving way to a fond smile. As she sat back against the chair, you returned her smile, hoping it eased her nerves. It appeared she wasn’t comfortable with Alter’s arrival either. As you drifted off to sleep, Nightingale kept a watchful eye over you.

 

Aside from the clear guard your servants kept when Cú Alter was around, things were normal by Chaldea standards. Save for Nightingale assigning herself as your room guard, you knew it made her comfortable though, so you didn’t fight her on letting her join you. Even Mash, though jealous at first seemed content with the arrangement. Even with all this going on, you still made an extra effort to take Alter on missions and training. He followed your commands without hesitation, to which you were grateful, but you could feel the distance he maintained as he avoided any casual contact or conversation. The most you’d really gotten him to say to you was when you’d first ascended him.

 

  “ _I feel most of my power has returned.”_ He had said with mild interest as he regarded you with a neutral expression. You merely smiled and nodded, thanking him for his hard work to which he merely shrugged.

 

  Your curiosity and determination getting the better of you, you began to push more to get along with the Berserker. As he’d gotten more accustomed to the layout of Chaldea, Alter was leaving his room a tad more often. Typically hanging out among other reserved servants who wouldn't bother each other or relaxing somewhere in solitude, you made an effort to create casual encounters with the man.

 

  “Hey Cú, how are you?” Not even a glance in your direction, he’d simply walked past you in the hallway.

 

“You did a great job against that chimera, was it a good fight for you?” A glance, but nothing more as returned his gaze to the snowy view of the large bay window in one of Chaldea’s hallways.

 

  “Its been quite a few days now, have you tried getting along with your other selves?” It was instant, it all happened so fast. With his deep red spear pointed at your heart, he growled at you.

 

  “Don’t stand so defenselessly in my presence. I just might gut you without thinking.” His expression of annoyance shifted to a bloodthirsty grin, exposing his sharp teeth. There were several reasons you did not flinch at his bold threat, his cursed spear still pointed at your heart. After so many battles, you were no stranger to a death threat. Another reason was that as swiftly as Alter had raised his spear to you, a small group of your other servants had surrounded you and him.

 

  Florence stood to the side with her gun poised and ready to fire at Alter’s head. Behind Alter, Lancer Cú held his Gáe Bolg prepared to strike at any sudden move. Caster Cú had an arm at your waist as his eyes narrowed at the offending weapon aimed at you while Proto Cú took a protective stance in front of you, ready to counter if the Berserker dared to strike you. It was a good thing you felt so safe and confident in their abilities, otherwise Mash would be breaking down walls to be at your side should she sense your fear.

 

  After a pregnant pause, you smiled at Alter Cú.

 

  “I didn’t mean to upset you, I just want to get to know you Alter.” His weapon was still aimed at your heart, yet you spoke without hesitation. Your servants remained at the ready, silent and focused to protect their Master and dear friend. The beastly grin on Alter’s face fell to a smirk as he lowered his weapon to his side, his crimson eyes trained on you.

 

  “Don’t think too hard about these things, I’m but a spear to you.” He muttered before letting his smirk drop to a sneer as he turned his attention to the servants still on guard to strike him.

 

  “I was wondering when you idiots would come out. You’re no assassins.” He chuckled darkly as he turned to fully look down at Lancer Cú. Cú Chulainn took the insult in stride as he stood in a semi- relaxed stance, his Gáe Bolg at his side as he wore a smirk as feral as Alter’s own from earlier.

 

  “It was more to see if you were stupid enough to try a stunt like this. Satisfied with the result, or do you really want to have a go?” the Lancer challenged as Florence narrowed her eyes at them.

 

  “I’ll ask only once that neither of you attempt such a brawl, especially while Master stands among us as potential collateral.” To punctuate her sentence, the click of her pistol resounded clearly. Caster sighed from beside you as he leaned down to whisper in your ear.

 

  “You’re not shaken up yeah?” Which you nodded in answer. The man gave a lopsided smile at you as he stood straighter and cleared his throat.

 

  “I’m hoping you’re not going to try something like this again?” His question was met with silence as Alter’s tail twitched. Lancer and Proto growled as they readied themselves to say something else, only for you to step forward and clear the air.

 

  “I think everything is okay now. It was really my fault for egging him on, so come on guys, let him go.” Florence seemed to ponder your words before wordlessly lowering her pistol and returning it to her holster. She brought herself to stand to opposite of Caster at your side while Proto exhaled in exasperation. He stood straight, bringing his spear to rest on his shoulder as he gave you a thoughtful glance and backed off.

 

  “Hmpf.” Lancer frowned as he twirled his spear before holding it behind his back. Stepping away from Alter, the two locked eyes as Lancer walked past him to stand in front of you. Alter said nothing as he walked away from your group, his cloak like a shadow as he left. Lancer’s attention on your face, he leaned down, his free hand pet the top of your head as he pecked your forehead.

 

   “I know, I know. I’ll be more careful next time. I see now that I can’t rush things.” You chuckled, praying it eased their tensions. You know it’d be some time before they move past this altercation. To them, they nearly lost their Master and more. _Sorry everyone, but I’m not giving up._


End file.
